Recent progress in passively stabilized single-frequency Brillouin fiber lasers with doubly-resonant cavities

摘要

Single longitudinal mode (SLM) fiber lasers have attracted interest due to many applications in optical fiber sensing and fiber optical communication. Among SLM fiber lasers, Brillouin lasers with doubly-resonant cavity demonstrate low threshold, low intensity noise and perfect spectral performance. Such lasers employ a short ring cavity that has to be simultaneously resonant for the pump and Stokes waves. For stabilization of such lasers against environment noise two tasks have to be solved: 1) to lock the generated pump radiation to the frequency of one of the cavity modes; 2) to adjust the ring cavity length such that the Brillouin frequency shift for the locked pump frequency be exactly equal to an integer number of the ring cavity mode spacing.